1. Technical Field
Example embodiments of the present invention relate in general to an antenna, and more particularly, to an antenna apparatus capable of generating a multi-beam pattern.
2. Related Art
These days, to provide mobile communication service, there is an increasing demand for an antenna that has a wideband or multi-band frequency characteristic in terms of frequency, and can project a beam in a specific direction or implement multiple beams.
An array antenna can project a main beam in a desired direction without physical movement, and generate a multi-beam pattern with one phase array. Due to such characteristics, the array antenna is mainly used to project a beam in a specific direction or generate a multi-beam pattern.
A beam pattern of the array antenna is determined according to shape, direction, and spatial position of individual antenna devices, and level and phase of a feeding current. Here, the level and phase of the feeding current are adjusted in a beamforming network. Also, when the number of array devices constituting the array antenna is N (here, N is a natural number equal to or greater than 1), the number of variables for adjusting a beam projection direction is N×2.
Thus, to generate a multi-beam pattern using a conventional array antenna, the level and phase of the feeding current need to be controlled. Also, the greater the number of array devices, the greater the number of variables to be controlled, and the more complex the array antenna becomes.